Formation and destruction of H2S in the short residence time pyrolysis of pulverized coal and model compounds

✍ Scribed by Thomas W. Lester; Jayram Polavarapu; Joseph F. Merklin

• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 673 KB
• Volume: 61
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(82)90169-7

✦ Synopsis

The evolution of sulphur as H,S from three US bituminous coals, L-cystine, and thianthrene has been studied in the reflected shock region of a chemical shock tube. With heating rates of approximately 3 x 1 O6 K s-', to temperatures in the range 1 OOO-2000K. ultimate yields of sulphur from 7 to 70% as H,S are observed in as little as 1.5 ms. The most important influence on ultimate yields may be the H/S molar ratio in the fuel which corresponds in the hydrocarbons studied with the H,S yields. Inherent mineral matter may also influence the evolution, as H,S formation precedes light hydrocarbon formation from the two model compounds, but occurs nearly simultaneously from the coals. The overall rate of H,S formation for the three coals is adequately described by a reaction, first order with respect to remaining sulphur, with a rateconstantk=8.1

x lO'exp( -15960/T) s-'. In the pyrolysisof allfivesolids, the H,S yields are decreased to below detectable limits at temperatures > 1500K. The path for destruction of the H,S appears to be by reaction with hydrocarbons such as &Hz, the concentration of which becomes similar to the H,S concentration in the temperature range 1500-l 600K.